Hiking is the most popular of outdoor activities, and not without reason. The most popular hiking routes are those in the Tatra Mountains but the Pieniny, the Bieszczady or the Karkonosze are all options. Canoeing is possible on most waterways, though the main rivers are pretty polluted. The Krutynia and Czarna Hańcza Rivers, both in Masuria, are almost untouched and have some of the best kayaking in the country. The Masurian lakes are ideal for sailing and, not surprisingly, they are crowded with hundreds of boats in summer. It’s possible to hire a sailing boat in Giżycko, Mikołajki or several other Masurian resorts. Poland has about a thousand caves, mostly in the uplands near Kraków and in the Tatra Mountains. For those unwilling to plunge into uncharted blackness, a handful of caves are adapted for the spatially-sane. The most spectacular of these are the Bear’s Cave near Kłodzko and the Paradise Cave near Kielce. Skiing is mostly concentrated in the Carpathians. Zakopane, at the foot of the Tatra Mountains is without a doubt ski-bunny warren numero uno, with Szczyrk in the Beskid Śłaski also popular.